| dc.description.abstract | In 2007, Bone morphogenetic protein -2 (BMP-2) protein has been used extensively in clinic. However, some information from Food and drug administration (FDA) data had revealed that BMP-2 protein could induce the complications frequently, such as cervical swelling and corresponding dyspnea and dysphagia requiring intubation. Among these, more than 20 to 70 % of cases were life threatening. Although FDA issued a warning in 2008 about the safety and efficacy of BMP-2 protein, BMP-2 remains the preferred option for orthopedic trauma. Many researchers are searching an alternative of BMP-2. Basically, BMP-2 protein functions through formation of hetero-tetrameric complex with type I and type II receptors of BMP. Many type II receptors has been revealed their increasing osteogenic signaling, such as bone morphogenetic protein receptor-II (BMPRII) and activin receptor (ACVR2A/2B). It became a potential target to limit the activity of BMP-2 through blocking BMPR2 by using antibodies, small molecules, aptamers and peptides. In spite of antibodies, small molecules and aptamers with their unstable drawbacks, peptides could be considered as a better alternative. Comparing with others, peptides was with their ease of synthesis, handling, biodegradability as well as low immunogenic activity. In this study, we designed a BMP-2-derived peptide with BMP-2 linear knuckle epitope (73-92). The linear peptide was cyclized by incorporating two cysteine residues into different sequence. Four cyclic peptides were prepared respectively. The active region in C-terminal of the peptide could be either inside or outside the cyclic structure. Then, BMPRII-blocking activity was performed by surface plasmon resonance (SPR). The SPR study showed that the peptides with an active region inside the cyclic ring had a higher binding affinity in comparison to the other peptides. In addition, the in-vitro activity caused by BMPR2 blocking was carried on myogenic C2C12 cell lines. After co-culture C2C12 with different peptides, BMP-2 signaling and osteo-differentiation were performed by western blotting of RUNX2 and staining of alkaline phosphatase (ALP). Based on the affinity data and the in vitro experiments, peptide P-05 could be a suitable candidate for osteogenesis, with higher binding affinity and increased RUNX2 and ALP expression in comparison to the linear peptides. | en_US |